Electric switch



June 9, 1953 M. F. KoENlG ET AL 2,641,671

ELECTRIC SWITCH Filed Dec. 27, 1949 2 Sheets-Sheet l |4|4f lab |45 June 9, 1953 M. F. KOENIG ET A1. 2,641,571

ELECTRIC SWITCH Filed Dec. 27, 1949 2 Sheets-Sheet 2 l CII llaldlobnu HC m5 Patented June 9, l1953 ELECTRIC SWITCH Martin F. Koenig, Milwaukee, and Ralph A. Millermaster, Whitefish Bay, Wis., assignors to Cutler-Hammer, Inc., Milwaukee, Wis., a corporation of Delaware Application December 27, 1949, Serial No. 135,088

This invention relates to electric isolating switches and more particularly to plug type front-operated switches of the push-pull type adapted for use in electrical control centers such as that shown in the Lightfoot Patent No. 2,319,415.

One of the problems encountered in the utilization of control centers such as that shown in the aforementioned Lightfoot patent has been that of providing for the safety of the workmen or electricians whose job it is to maintain and repair such centers. As will be understood, control centers of the type under consideration are made up of a plurality of individual, complete control units readily removable from the supporting and enclosing structure of the control center. Normally such control units include a disconnect switch, which may or may not be interlocked with the door covering the particular control unit, which disconnect switch is adapted to break the electrical circuit to the lead. However, when it becomes necessary to repair or remove the control unit from its supporting structure, while the load is disconnected, there still remain live leads connecting the control unit to the source of electrical energy, and more particularly to the line busses of the control center. The presence of such live leads is obviously of considerable hazard to the electrician or maintenance man.

Accordingly an obj ect of the present invention is to provide aV switch for isolating control units of the aforementioned character from their respective sources of electrical energy before repair or removal thereof from their supporting and enclosing casings.

Another and more specific object is to provide an isolating switch of the aforementioned character having means for preventing accidental closing of the circuit through such isolating switch.

Another object is to provide an isolating switch of the aforementioned character wherein the position of the switch may be readily ascertained.

A further object is to provide a switch of the aforementioned character wherein the possibility of accidental touching of the live parts of the switch by one operating the switch is substantially prevented.

Other objects and advantages of the invention will hereinafter appear.

The accompanying drawings illustrate a preferred embodiment of the invention, it being understood that the embodiment illustrated is susceptible of modification within the scope of the appended claims.

8 Claims. (Cl. 20G- 169) In the drawings,

Figure 1 is a top plan view of the switch shown in the closed position;

Fig. 2 is a side elevation from the left of the switch shown in Fig. l; the switch, however, being shown in the open position;

Fig. 3 is a sectional view taken on the line 3--3 of Fig. 1;

Fig. 4 is a fragmentary section taken on the line 4 4 of Fig. 1, but showing the switch in the open position and more particularly illustrating means for preventing accidental closure of the switch; and

Fig. 5 is a top plan View, similar to that of Fig. l, of a portion of the switch, but with the cover member removed and the switch parts in open position. Y

Referring to the drawings, the numeral II) designates a molded base of a suitable insulating material, such as Bakelite As best shown in Figs. 2 and 5, base I!! is yformed with a plurality of transverse slots I!)EL at the bottom of which are mounted pairs of spaced cooperating stationary contacts Il, the number of such slots and pairs of stationary contacts depending upon the number of poles desired in the switch (the switch illustrated being a 3-pole switch). As best shown in Fig. 3, each of said stationary contacts II preferably comprises an L-shaped member IIB and a correspondingly shaped resilient spring member IIb; said members IIb tending to urge the free end portions of said pair of members IIa toward each other, and said members IIa and I Ib being attached jointly to the bottom surface of the respective slot Illa, as shown, for example, by means of a bolt and nut IIC. Each of said contact members I Ia also has attached thereto at the outer end thereof a terminal lug IId preferably of the solderless type and of well known form.

Base I0 is also provided with a longitudinal recess I0b (Figs. 1, 3 and 5) extending downwardly from the top surface thereof, as best shown in Fig. 3, said recess II)b being so dimensioned as to receive with a free sliding t the full width portion of a flat insulating plate I2 comprising a bridging contact carrierrand switch operator. Contacts Il'are so positioned in slots I Ila as to have interposed between each pair thereof some portion of plate I2.

As best shown in Figs. 1, 2 and 3, plate I2 carries a bridging contactor I3 for each pair of stationary contacts, plate I2 being adapted to slide within recess IIJb in a manner to effect simultaneous movement of contactors I3 into or out of bridging engagement with the respective sets of contacts I I, II. For this purpose plate I2 is provided at its outer end with an operating or handle portion I2a to be grasped by the operator to push or pull plate I2 as the case may be, to selectively open and close the electrical circuit through the switch.

I'he switch is provided with a flat cover member I4 of insulating material (Fig. 3) having appropriate markings or legends as best shown in Fig. 1, said cover member I4 being slotted as at llia to afford projection therethrough of the handle portion I2a of contact carrier I2. The

slot III2t is of the shape best shown in Fig. 1 and preferably is shorter in length than recess II]b underlying it, the. handle portion I2*EL of contact carrier I2 preferably being reducedv in width to form a shoulder as at I2b (Fig. 2) to engage the lower face of cover member I4 thereby limiting outward displacement of member I2 and also affording indication of the fact that the switch is in the open or off position. Cover member is attached to base I as by means of screws IIIb (Fig. l).

To prevent accidental closure .of the switch a spring biased latching means is provided (see Fig. 4) comprising an L-shaped latching member I5 adapted for sliding movement in a recess I0 in the upper surface of base I0. (Fig. 5), cover member Ill preventing upward displacement of member I5 and being notched as at Ide (Figs. 1 and 4) to permit transverse movements of member I5. Asbest shown in Fig. 4, plate I2 is slotted as at I 2C to accommodate the inner end of latching member I5 to lock plate I2 in the open position. Member I5 is shown as provided with an integral downwardly extending lug I5a to be engaged by a compression spring I6 disposed below latching member I5 in a recess Illd opening upwardly to the aforementioned recess Il!c in base Il), said spring being compressed between the end wall of recess Illd and lug I5a to urge latching member I5 at all times against plate I2. As will be apparent, as plate I2 is pulled outwardly slot I2c therein will become alined with the inner end of latching member I5 and the latter under the bias. of spring I6 will enter into slot I2c to latch the switch in the openposition. Y

While the aforementioned safety latching arrangement positively prevents accidental closure of the switch, it will be apparent-that the operating means I2 may be simply unlatched when the operator grasps the handle portion lf2a and extends his fingers through the opening formed thereby to easily slide latching member I5 to the left with his finger tips, from the position thereof shown in Figs. 4 and 5, to permit manual closure of the switch.

An additional safety means, to prevent the operator from accidentally placing his lingers in contact with the live line side terminals or stationary contacts when closing or opening the switch, consists of an L-sha-ped insulatingcover I'I attachedto base VIll as by screws I'Ia' and enclosing the righthand open ends of slots It),av into which the operator might accidentally insert a fingerV or fingers. Thu-s the topand right hand sides of the switch are substantially enclosed to prevent accidental contact with live parts.

We claim:

1. A front operated manual plug-type isolating switch having a push-pull' operating member having a. transverse opening therethrough anda flat latching member for extending through said ber in its outermost or'sWitch-opening position,

4 thereby to prevent accidental closure of the switch, said latching member being disposed adjacent said operating member to aiord sequential unlatching thereof and closure of the switch by one hand of an operator.

2. A front operated manual plug-typeA isolating switch having a push-pull operating member comprising an insulating plate having an opening therethrough, and latching means for locking said operating member in its outermost or switchopening position to prevent accidental closure or the. switch, ysaid latching means comprising a flat member slidable through said opening to lock said operating member.

3. A front operated manual plug-type isolating switch having a. push-pull operating member comprising a iiat insulating plate having ay transverse slot therethrough, and latching means for locking said operating member in its outermost or switch-opening position to prevent accidental closure of the switch, said latching means comprising ,a flat member slidable into and outI of said slot, and spring biasing means underlying Said ilat latching member for urging the latter toward said operating member and eiecting passage thereof through said slot when said 0D- erating member is pulled to its said outermost position.

i. A front operated lollig-typ@ isolating Switch comprising an insulating base having a longitudinal recess opening to the front surface thereof and having at least one. transverse slot, a pairv of cooperating and spaced stationary contacts mounted in said slot, a combined operating member and bridging contacter carrier comprising a nat insulating plate disposed Within said longitudinal rrecess with a free sliding nt and being interposed between said stationary contacts at all times, said operating member having mounted thereon a contacto-r for bridging said stationary contacts when said ope-rating member is in its innermost position, and latching means for preventing accidental movement of said operating member to its innermost position comprising a flat sliding member adapted for passage through an opening in said operating member when in its outermost. position, and spring means underlying said sliding member to urge the latter through the opening in said operating member to; automatically eiTect latching of the latter when .the aforementioned opening therein becomes. alined with said sliding member.

5. A iront operated plug-type isolating switch comprising an insulating base having a longitudinal recess opening to the front surface thereof and having at least one, transverse slot, a pair of cooperating and spaced stationary contacts mounted in said slot, a, combined operating member and bridging contactor carrier comprising a flat insulating plate disposed within said longitudinal recess with a free sliding ntand being interposed between said stationary contacts at all times, said operating member having an opening therein and` also having mounted'thereon a contactor for bridging said stationary contacts when said operating Amember, is in its `innermost position, and latching means for preventing accidental movement of said operating .member to its innermost position comprising a flat sliding member adapted for passage through said opening in said operating member when in its outermost position, and spring means urging said sliding member toward said operating member to. automatically eieetV latching of. the latter when the aforementioned opening therein becomes alined with said sliding member, and an insulating cover member for maintaining said sliding member in assembled position and to shield live parts of the switch.

6. A front operated manual plug-type isolating switch having a push-pull operating member comprising a flat insulating plate having a transverse slot therethrough and having a handle portion, and latching means for locking said operating member in its outermost or switchopening position to prevent accidental closure of the switch, said latching means comprising an L-shaped member slidable into and out of said slot and spring biasing means for urging said slidable member toward said operating member and automatically effecting passage of one arm of said slidable member through said slot when said operating member is pulled to its said outermost position and said slot is in alinement with said one arm of said slidable member, the other arm of said slidable member being positioned adjacent to said handle portion of said operating member to provide for sequential unlatching thereof and closure of the switch by one hand of an operator.

7. A front operated plug-type isolating switch comprising an insulating base having a longitudinal recess opening to the front surface thereof, an operating member disposed within said longitudinal recess with a free sliding nt and having a slot, said insulating base also having a shallow transverse recess in the top surface thereof extending to either side of said longitudinal recess, a latching member slidable in said transverse recess adapted to pass through said slot in said operating member and into that portion of said transverse recess lying on the opposite side of said operating member, and a cover member overlying said transverse recess to maintain said latching member in assembled position, passage of the latter through said slot af fording latching of said operating member against movement in either direction.

8. A front operated plug-type isolating switch comprising an insulating base having a longitudinal recess opening to the front surface thereof, an operating member disposed within said longitudinal recess with a free sliding fit and having a small slot, said insulating base also having a shallow transverse recess in the top surface thereof extending to either side 0f said longitudinal recess, a nat L-shaped latching member one arm of which is slidable in said transverse recess and is adapted to pass through said slot and into that portion of said transverse recess on the opposite side of said operating member, a cover member overlying said transverse recess to maintain said latching member in assembled position, and biasing means underlying said latching member to urge the latter toward said operating member to automatically lock the latter when said slot therein and said latching member are in registry, the other arm of said latching member in this position of the switch being adjacent said operating member to alford unlatching of the operating member and movement thereof by one hand of an operator.

MARTIN F. KOENIG. RALPH A. MILLERMASTER.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 896,495 Wentz Aug. 18, 1908 1,952,372 Grace Mar. 27, 1934 2,091,148 Hughes et al. Aug. 24, 1937V 2,129,591 Schneider Sept. 6, 1938 2,200,322 Arnesen May 14, 1940 

